试题库在线考试题库-历年真题模拟试题及答案-考博英语在线试题测试中心-希赛网

清华大学

Directions: For this part, you are allowed 50 minutes to write a composition of no less than 300 words under the title of “Advantages and Disadvantages of Doing Research Online.” Your composition should be based on the following outline:1) Present situation about doing research online;2) Advantages for online research;3) Disadvantages for online research.

For most of human history, the dominant concerns about energy have centered on the benefit side. Inadequacy of energy resources or of the technologies for harvesting, converting, and distributing those resources has meant insufficient energy benefits to human beings and hence inconvenience, and constraints on its growth. The 1970’s，then, represented a turning point. Energy was seen to be getting costlier in all respects. It began to be believable that excessive energy costs could pose threats on a par with those of insufficient supply. It also became possible to think that expanding some forms of energy supply could create costs exceeding the benefits.The crucial question at the beginning of the 1990's is whether the trend that began in the 1970’s will prove to be temporary or permanent. Is the era of cheap energy really over, or will a combination of new resources, new technology and changing geopolitics bring it back? One key determinant of the answer is the staggering scale of energy demand brought forth by 100 years of population growth and industrial demand.Except for the huge pool of oil underlying the Middle East, the cheapest oil and gas are already gone. Even if a few more giant oil fields are discovered, they will make little difference against consumption on today’s scale. Oil and gas will have to come increasingly, for most countries, from deeper in the earth and from imports whose reliability and affordability cannot be guaranteed.

The changes in globally averaged temperature that have occurred at the Earth’s surface over the past century are similar in size and timing to those（1）by models that take into account the combined influences of human factors and solar variability. To （2） the question of attribution requires the （3） of more powerful and complex methods beyond the use of global averages alone. New studies have focused on（4） maps or patterns of temperature change in （5） and in models. Pattern analysis is the climatologically equivalent of the more comprehensive tests in the medical analogy mentioned（6）, and makes it possible to achieve more definitive（7）of the observed climate changes to a particular cause or causes.The expected influence of human activities is thought to be much more complex than uniform warming over the entire surface of the Earth and over the whole（8） cycle. Patterns of change over space and time therefore provide a more powerful （9） technique. The basic idea（10）pattern-based approaches is that different（11）causes of climate change have different characteristic patterns of climate response or fingerprints. Attribution studies seek to（12） a fingerprint match between the patterns of climate change（13） by models and those actually observed.The most recent assessment of the science suggests that human activities have led to a discernible （14）on global climate and that these activities will have an increasing influence on future climate. The burning of coal, oil and natural gas, as well as various agricultural and industrial practices, are（15）the composition of the atmosphere and contributing to climate change. These human activities have led to increased atmospheric （16） of a number of greenhouse gases, including carbon dioxide, methane and so on in the lower atmosphere.Human activities, such as the burning of fossil, have also increased the （17） of small particles in the atmosphere. These particles can change the（18） of energy that is absorbed and reflected by the atmosphere. They are also believed to modify the（19） of air and clouds, changing the amount of energy that they absorb and reflect. Intensive studies of the climatic effects of these particles began only recently and the overall（20）is uncertain. It is likely that the net effect of these small particles is to cool the climate and to partially offset the warming of increasing concentrations of greenhouse gases.

The difference between avian flu and human flu that should be commanding our rapt attention today is that avian influenza, specifically the H5N1 strain known as bird flu, threatens to become the young people’s plague. And it is a growing contender to cause a devastating worldwide pandemic in the next few years.We are too used to thinking of flu as an annual annoyance that kills only the frail and elderly. But that just isn’t the case for H5N1. With a mortality rate of over 50 percent, this bird flu has killed over 110 people, striking the young and able-bodied the hardest. Its victims cluster predominantly among 5- to-30-year-old, a pattern that has held up in the 34 known to have died from bird flu so far this year.This vulnerability may stem from the robust and fast-responding immune systems of the young. The victims overreact to the alien virus, triggering a massive immune response called a cytokine storm, turning healthy lungs into a sodden mass of dying tissues congested with blood, toxic fluid, and rampaging inflammatory cells. As air spaces choke off, the body loses oxygen and other organs fail.Scientists have recently shown that H5N1 has ominous parallels with the devastating 1918 flu pandemic, which also jumped directly to humans from birds and disproportionately attacked the young and the strong. With a pattern highly suggestive of a cytokine storm, death sometimes came within just hours, turning many World War I troop ships into death ships.Now imagine hundreds of thousands of young people laboring on respirators, or lying alone in corridors and makeshift hospital rooms, too sick to be helped when the supply of beds, equipment, and trained staff run out. Seem like hype? Not to the medical experts who discussed these scenarios during last week’s t/. 5*. News Health Summit on emergency preparedness.This picture puts a face on the U. S. Department of Health and Human Services, projections that, ifH5N1 mutates into a readily human-transmissible from 209, 000 to 1.9 million Americans could die. Part of our readiness thinking should be to heed the blunt words of HHS Secretary Michael Leavitt at the summit: Any family or community that fails to prepare for the worst, with the expectation that the federal or state government will come to the rescue, will be “tragically wrong.” In a pandemic, the government’s medical resources will be stretched thin, and it won’t be able to guarantee first-line help to any hometown, local hospital, or college campus. Even the national stockpile of Tamiflu, the antiviral that is the best we have to prevent or lessen the impact of the illness, has its limits. If a college student is hospitalized with a possible H5N1 infection, the feds will provide drugs. But they will not make it available to fend off the virus in the many others who may have come in close contact with the infected student. In the existing federal guidance on H5N1, the young and healthy fall into the lowest-priority group for antiviral drugs and vaccines. Student health centers or other providers had better scrounge up their own stockpiles. Containing possible outbreaks on college campuses may be all but impossible. Social distancing — avoiding close contact with other people with air kisses instead of smooches, or even by donning masks and gloves — will be tough to enforce.The threat poses a uniquely difficult challenge. In the best of all scenarios, the virus will lose its fury and leave in its wake a new culture of individual and community preparedness. But we need to get ready now, and not for the best scenario but for the worst.1.The difference between avian flu and human flu is that（） .2.The reason that bird flu strikes the young and able-bodied the hardest may be（） .3.According to the author, which is the best source that college students can rely upon if there are outbreaks of bird flu on college campuses?4.We can learn from the passage that（） .

In a year marked by uncertainty and upheaval, officials at New Orleans universities that draw applicants nationwide are not following the usual rules of thumb when it comes to college admissions. The only sure bet, they say, is that this fall’s entering classes — the first since Katrina 一 will be smaller than usual.In typical years, most college admissions officials can predict fairly accurately by this point in the admissions cycle how many high school seniors will commit to enrolling in their institutions. Many of the most selective schools require students—who increasingly are applying to multiple institutions — to make their choices by May 1. Loyola University, whose trustees will vote May 19 on whether to drop several degree programs and eliminate 17 faculty positions, received fewer applications — about 2, 900 to date, compared with 3, 500 in recent years. The school hopes to enroll 700 freshmen, down from 850 in the past few years. Historically black Dillard University, which is operating out of a hotel and was forced to cancel its annual March open house, also saw drops, as did Xavier University, a historically black Catholic institution that fell behind its recruitment schedule. Dillard won’t release numbers, but spokeswoman Maureen Larkins says applications were down and enrollments are expected to be lower than in the past. Xavier admissions dean Winston Brown says its applicant pool fell by about half of last year’s record 1, 014; he hopes to enroll 500 freshmen.In contrast, Tulane University, which is the most selective of the four and developed an aggressive recruitment schedule after the hurricane, enjoyed an 11% increase in applications this year, to a record 20, 715. Even so, officials predict that fewer admitted students will enroll and are projecting a smaller-than-usual freshman class — 1, 400, compared with a more typical 1, 600. Tulane officials announced in December that they would eliminate some departments and faculty positions.Like Tulane, other schools are taking extra steps this year to woo admitted students, often by enlisting help from alumni around the country and reaching out to students with more e-mails, phone calls or Web-based interactions such as blogs. In addition, Loyola is relaxing deadlines, sweetening the pot with larger scholarships and freezing tuition at last year’s level. Dillard, too, is freezing tuition. It’s also hosting town meetings in target cities and regions nationwide, and moved its academic calendar back from August to mid-September “to avert the majority of the hurricane season,’’ Larkins says. Xavier extended its application deadline and stepped up its one-on-one contact with accepted students. And Tulane, among other things, has doubled the number of on-campus programs for accepted students and hosted a community service weekend program.While the schools expect applicants to be apprehensive, the admissions officials also see encouraging signs of purposefulness among applicants. “A lot of students who are choosing to come to this city (are) saying, ‘I want to be a part of (the action)'", says Stieffel, noting that Loyola’s transfer applications were up 30%. And while applications to Xavier are down, Brown is betting that students who do apply are serious. “The ones who are applying, we feel, are more likely to come,” he says.1. It can be inferred from the passage that（） .2.The following statements are false other than （）.3.In order to attract applicants, Loyola University and Dillard University are（） .4.The passage mainly concentrates on the subject of（） .

上一页

1 / 15